A. Field of the Invention
The invention relates to a stator of a torque converter, and particularly a stator of a torque converter having thin blades.
B. Description of the Background Art
A torque converter typically includes an impeller, a turbine and a stator, and is operable to transmit torque via a working fluid that fills an interior thereof. The working fluid operates for transmitting torque in a radially outer region of the torque converter flowing from the impeller to the turbine, and then flows from the turbine to the stator, and subsequently flows back to the impeller.
The stator is disposed between the impeller and the turbine in a radially inward portion of the torque converter. The stator is usually supported on a one way clutch mechanism. The one way clutch mechanism is typically supported on a stator shaft that is fixed to a transmission housing. The stator is usually made of a casting of resin or aluminum alloy or other metal materials, and is basically formed of an annular outer shell, an annular inner shell and blades disposed between the outer shell and inner shell.
The blades of the stator are arranged at a plurality of circumferentially spaced apart, aligned positions, respectively, and each blade extends from the radially inner shell to the radially outer shell for controlling a direction of the working fluid returning from the turbine to the impeller. The blades are shaped such that the sectional area of each blade changes at a substantially constant rate through its entire radial length, except for a portion which will hereafter be referred to as a "corner portion". The corner portion forms a boundary region between the blade and the shell. Typically the blade and the corner portion are formed integrally with each other by the casting methods mentioned above. The outer surfaces of the blades are arcuately shaped.
For improving a torque transmission efficiency of the torque converter, it is necessary to provide an optimum fluid performance at the stator in accordance with the forms of the impeller and stator. For this, it is generally desirable to minimize a thickness of the blade of the stator in order to optimize the performance of the stator within a wide range.
Although reduction in thickness of the blade is desired for improving the performance, increase in thickness thereof is required in order to insure the structural strength of the blades.